<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <style>
        /* show Rending 查看重绘操作 */
        @keyframes rotate {
            from {
                transform: rotate(0deg);
                /* width: 100px; */
            }
            to {
                transform: rotate(360deg);
                /* width: 500px; */
            }
        }
        #app{
            width: 100px;
            height: 100px;
            background:red;
            animation:rotate  0.2s linear infinite
        }
    </style>
    <div id="app"></div>

    <div style="opacity: 0.2;">my</div>
    
</body>

</html>